<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    var str='hello32123123123123'
    var arr=[3,2,1]
    var arr2=[
            {name:'aa',age:18},
            {name:'bb',age:20},
        ]
    var json={
        name:'hello',
        age:18
    }
    console.group('lll');
    console.log(str.substring(3,2))
    console.log(str.substring(3))
    console.dir(str.indexOf('l'))// 数组indexof
    console.log(str.indexOf('l'))// 数组indexof
    console.table(str)
    console.table(arr)
    console.table(arr2)
    console.table(json)
    console.dir(str)
    console.dir(arr)
    console.dir(arr2)
    console.dir(json)
    console.log(str)
    console.log(arr)
    console.log(arr2)
    console.log(json)

    var a=333+undefined
    console.log(a);
    var b='333'+undefined
    console.log(b);
    // var c='333'+d
    // console.log(c);

    var person = {
        name: '小明',
        age: 20,
        gender: 'male',
        passport: 'G-12345678',
        school: 'No.4 middle school',
        address: {
            city: 'Beijing',
            street: 'No.1 Road',
            zipcode: '100001'
        }
    };
    var {name, address: {city, zip}} = person;
    console.log(name);
    var x=1, y=2;
    [x, y] = [y, x]
    console.log(x);
    var {hostname:domain, pathname:path} = location;
    console.table(location);


</script>
</html>